The present invention relates to a toner container and a method and an apparatus for forming an image by using the same.
An electrophotographic image forming apparatus of the type developing a latent image formed on an image carrier with toner stored in a developing unit is conventional. This type of image forming apparatus is implemented as, e.g., a copier, a printer, a facsimile apparatus or a combination thereof. Fresh toner is replenished form the toner container to the developing unit for development.
Usually, the toner container is removably mounted to the body or the developing unit of the image forming apparatus and replaced when it runs out of toner. After the toner container has been packed with toner, it is put on the market as a product independent of the apparatus body.
Japanese Patent Laid-Open Publication No. 7-20705, for example, discloses a toner container formed with a spiral groove in its inner periphery toward a toner outlet or mouth. When the toner container is rotated about its axis, toner is fed out via the spiral groove. This toner container is formed of, e.g., plastics. On the other hand, Japanese Patent Laid-Open Publication No. 7-281519 teaches a toner container having thereinside an agitator for delivering toner and formed with plastics or paper. The agitator is rotated to feed out toner while agitating it. The toner containers taught in the above documents both are hard toner containers each having a toner discharging mechanism thereinside.
Toner driven out of any one of the above toner containers by the toner discharging mechanism directly drops into a hopper included in the developing unit. The toner is conveyed from the hopper to a developing position for developing a latent image formed on an image carrier. It is therefore necessary to locate the toner container in the vicinity of the developing unit in the image forming apparatus. In addition, considering the drop of the toner, it is necessary to locate the toner container above the developing unit unless some special mechanism is used. To meet these requirements, the toner container has customarily been considered to be integral with the developing unit and provided with an exclusive space in relation to the layout of various means and parts arranged in the image forming apparatus.
The prerequisite with the image forming apparatus is that the delivery of toner from the toner container to the developing unit be continuous and stable. However, the above conventional system for replenishing toner from the toner container to the developing unit cannot sufficiently meet this prerequisite, limiting image quality available with the apparatus. Another problem is that some of the toner stored in the toner container is left in the container without contributing to image formation and simply wasted.
Attention has not been paid to the above problems or solutions thereto in the past.